• 한국식생활문화학회지
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• 제5권2호
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• pp.229-233
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• 1990

Changes in chemical components of green tea leaves at different cooking conditions-blanching and frying-were surveyed as a method of utilizing low graded green tea leaves which missed appropriate plucking times. There was no significant difference in protein content during cooking. But contents of chlorophyll, tannin, vitamin C and caffeine were decreased during cooking, contents of chlorophyll and caffeine showed a greater decrease in frying than blanching. Content of total amino acid of green tea leaf was 15.8% and blanching showed bigger diminution of its content in comparision with frying during cooking.

• Journal of Nutrition and Health
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• 제32권4호
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• pp.337-352
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• 1999

The effects of dried leaf powders and ethanol extract of persimmon, green tea and pine needle on lipid metabolism, lipid peroxidation and antioxidative activity were investigated in rats. Forty-nine male Spargue-Dawley rats weighing 107.8$\pm$1.8g were blocked into seven groups according to body weight. Rats were raised for four weeks with diets containing either 5%(w/w) dried leaf powders of one of three different Korea traditional teas, persimmon(Diospyros kaki Thunb), green tea(Camellia Sinensis O.Ktzc)or pine needle(pinus Koreansis Sieb. Et Zucc), or ethanol from equal amounts of each dried tea powder. Food intake, weight gain, food efficiency ratio, and weights of liver, kidney and epididymal fat were significantly higher in the green-tea-powder group, and significantly lower in the pine-needle-powder and pine-needle-extract groups. Persimmon-leaf powder was found to decrease plasma total lipid, triglyceride and cholesterol concentration by increasing fecal total lipid triglyceride and cholesterol excretions. Liver cholesterol concentration was significantly lower in the green-tea and pine-needle-extract groups. Red-blood-cell superoxide dismutase(SOD) and glutathione peroxidase(GSH-px) activities were significantly increased in rats fed green-tea extract. Liver SOD activity was increased in rats fed pine-needle powder or extract, and liver GSH-px activity was increased in rats fed greentea powder. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentration were both decreased in rats fed dried leaf posers or extracts of persimmon or green tea. It is believed that high vitamin E levels in persimmon leaf, and high flavonoid, beta-carotene and vitamin C levels in green tea effectively inhibited lipid peroxidation. In conclusion, persimmon and green tea leaves were effective in lowering lipid levels and inhibiting lipid peroxidation in animal tissue, while pine needles were effective and lowering body weight gain. From these results, persimmon and green tea leaves can be recommended in the treatment and prevention of chronic discorders such as cardiovascular disease, cancer and aging. As ethanol extracts from these teas were also effecitive in lowering tissue lipid levels and inhibiting lipid peroxidation, we recommend the use of discarded tea grounds for this.

• 한국환경보건학회지
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• 제32권1호
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• pp.53-59
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• 2006

This study was carried out to investigate the physicochemical characteristics with the elapsed time of $1\~10$ minutes after adding green tea leaves in the tap water. The results are summarized as follows: 1. $UV_{254}$ measurement increased sharply in direct opposition to increasing conductivity slowly. It is expected that the water soluble organic matters were better extracted than minerals. 2. Residual chlorine decay coefficients evaluated by assuming first-order reaction was increased in proportion to adding weights of green tea leaves. 3. In DBP formation experiments, residual chlorine decreased when reaction time was elapsed. whereas DBPs such as HAAs and THMs increased with the passing of time. From these results, it was showed that residual chlorine decay was related with the formation of DBPs. Therefore, use of boiled tap water in preparation of green tea is suggested if the residual chlorine in the tap water is high.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.966-976
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• 2019

Objective: The methane mitigating potential of various plant-based polyphenol sources is known, but effects of combinations have rarely been tested. The aim of the present study was to determine whether binary and 3-way combinations of such phenol sources affect ruminal fermentation less, similar or more intensively than separate applications. Methods: The extracts used were from Acacia mearnsii bark (acacia), Vitis vinifera (grape) seed, Camellia sinensis leaves (green tea), Uncaria gambir leaves (gambier), Vaccinium macrocarpon berries (cranberry), Fagopyrum esculentum seed (buckwheat), and Ginkgo biloba leaves (ginkgo). All extracts were tested using the Hohenheim gas test. This was done alone at 5% of dry matter (DM). Acacia was also combined with all other single extracts at 5% of DM each, and with two other phenol sources (all possible combinations) at 2.5%+2.5% of DM. Results: Methane formation was reduced by 7% to 9% by acacia, grape seed and green tea and, in addition, by most extract combinations with acacia. Grape seed and green tea alone and in combination with acacia also reduced methane proportion of total gas to the same degree. The extracts of buckwheat and gingko were poor in phenols and promoted ruminal fermentation. All treatments except green tea alone lowered ammonia concentration by up to 23%, and the binary combinations were more effective as acacia alone. With three extracts, linear effects were found with total gas and methane formation, while with ammonia and other traits linear effects were rare. Conclusion: The study identified methane and ammonia mitigating potential of various phenolic plant extracts and showed a number of additive and some non-linear effects of combinations of extracts. Further studies, especially in live animals, should concentrate on combinations of extracts from grape seed, green tea leaves Land acacia bark and determine the ideal dosages of such combinations for the purpose of methane mitigation.

• 한국약용작물학회지
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• 제10권5호
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• pp.379-383
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• 2002

차광한 차나무 잎의 엽위별 생육특성 및 차 품질 관련 주요 화학성분을 분석한 결과는 다음과 같다. 하위엽으로 내려 갈수록 엽장, 엽폭, 백아중은 컸으나 엽수분은 감소하였다. 하위엽으로 내려갈수록 total nitrogen, caffeine, vitamin C, saponin 함량은 감소하였고, total amino acid, chlorophyll 함량은 4번 엽과 3번엽에서 각각 최대함량을 나타냈다. tannin은 $9.53{\sim}11.24%$로 1엽이 11.24%로 함량이 제일 많았고 4엽이 9.53%로 가장 적었다. fatty acid는 2엽에서 3,594mg/100g으로 함량이 가장 많았고, 5엽에서 2,782mg/100g으로 함량이 가장 적었다. 포화지방산인 palmitic acid와 steatic acid는 5엽에서 함량이 많았고, 불포화 지방산인 oleic acid, linoleic acid, linolenic acid는 2엽에서 함량이 많았다. 이상 분석 결과로부터 15일간 차광한 후 채엽한 가루녹차 원료는 5엽까지 채취하여 제다해도 품질에 있어서 큰 문제가 없다고 생각된다.

• 한국식품과학회지
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• 제40권5호
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• pp.485-490
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• 2008

본 연구는 유기농 녹차 음료를 개발하기 위해 유기농 다엽의 카테킨류 함량을 비롯한 물리화학적 특성을 분석하였다. 다엽은 일체의 화학비료와 농약을 사용하지 않고 유기농 기법으로 재배한 시료를 사용하였고 채취시기가 다른 4월, 5월, 6월차와 반발효차를 수매하여 실험에 사용하였다. HPLC를 이용하여 다엽의 카테킨류 함량을 정량 정성 분석하였으며 녹차추출물의 색도와 pH를 측정하였다. 0.5%의 4월, 5월, 6월, 반발효차의 카테킨류는 각각 66.24, 29.19, 57.11, 5.27 ${\mu}g/mL$을 함유하고 있었으며, 카테킨류 중에서 EGCg의 함량이 가장 높았으나 EGC는 검출되지 않았다. 유기농 녹차 음료의 생산을 위해 카테킨류의 함량, 다엽의 가격, 수확량을 고려하여 6월차를 선택하였다. 6월차를 0.05, 0.1, 0.2, 0.5%로 추출하여 카테킨류를 정량한 결과, 0.1, 0.2, 0.5%는 0.05%에 비해 각각 1.50, 11.78, 41.09배 증가하였다. 6월차는 농도가 증가할수록 밝기가 증가하였고, 가장 밝고 녹색과 황색의 색이 짙었다. 반발효차의 pH는 5.83이었으며 나머지는 6.33-6.38의 범위를 가졌다. 6월차의 기호도 및 관능평가를 실시한 결과, 색상 기호도는 0.1%, 향기호도와 전체적인 기호도는 0.2% 추출물이 가장 우수한 평가를 받았고 단맛, 신맛, 떫은 맛의 정도를 평가한 결과 0.2%가 음용하기에 가장 적절하리라 사료된다. 또한 음료 제작 후, 저장 기간에 따른 녹차의 색 변화를 줄이기 위해 저장성 실험 결과 탄산수소나트륨을 0.03%를 첨가할 필요가 있다.

• 한국식품영양학회지
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• 제31권5호
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• pp.647-652
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• 2018

Extracts from bay leaves, Chongbaek (Allium fistulosum L.), Hutgae (Hovenia dulcis Thunb.) fruit, and green tea, using Soju (Korean alcohol, $30^{\circ}$) as a solvent were analyzed for their antioxidative properties. The eels were evenly coated with the extract concentration equivalent to 2% of their total weight and dried for 15 hours at $35^{\circ}C$ using an air blower. The DPPH radical scavenging effect, acid value and peroxide value of semi-dried eel, and linoleic acid peroxidation of eel oil were investigated. The highest level of DPPH radical scavenging was found in green tea extracts, followed by Hutgae fruit extract and bay leaves extract (p<0.05). The acid value and peroxide value of Hutgae fruit extracts coated eels refrigerated for 21 days were the lowest followed by the green tea extract coated eels. During the 20 days reaction period, all four kinds of extracts analyzed were found to effectively decrease linoleic acid peroxidation. Among them, Hutgae fruit and green tea extracts decreased the peroxide content of eel oil steadily and for a longer period when compared to other extracts. In conclusion, pre-application of Hutgae fruit and green tea extracts on eels before drying was found to be effective in delaying peroxidation in eels during the drying process and refrigeration.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.189-193
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• 2000

Preservative and antimutagenic effects of green tea leaves added Chinese cabbage kimchi (GK1, GK2, GK3, and GK4 : 1, 2, 3 and 4 of green tea leaves (GTL) in proportion of 100 of salted Chinese cabbage were added to kimchi) were compared to those of the Chinese cabbage kimchi without GTL (control kimchi, CK). Fermentation period of GKs was further delayed than that of CK. The initial pH and acidity between GKs an CK were similar, but the time reach optimally ripened status of kimchi (pH 4.3) was different. CK took 6 days, while GK1, GK2, GK3 and GK4 took 6, 10, 12 and 14 days at 10℃, respectively. The growth of Leuconostoc sp. and Lactobacilus sp. in GKs delayed comparing to those in FCK. Among GKs, as the added amount of green tea leaves increased, the growth of lactic acid bacteria was retarded. The antimutagenic effects of juices from GKs and CK were studied against aflatoxin B₁(AFB₁) in the Ames test on Salmonella typehimurium TA100 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the SOS chromotest using E. coli PQ37. Juices from optimally ripened GKs (pH 4.3) showed 52∼76% inhibition rates against the indirect mutagen, aflatoxin B₁ induced mutagenicity while 49% inhibition rate by CK in the Ames test. Juices from GKs and CK showed 44∼67% and 36% inhibition rate against direct mutagen, MNNG (70 ng/assay) induce mutagenicity in the SOS chromotest. Thus GKs delayed fermentation period of kimchi and exhibited higher antimutagenic activity than CK.

• 한국식품과학회지
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• 제24권4호
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• pp.315-319
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• 1992

제주도 다원에서 생산된 녹차 생엽을 적채 시기별(1번차, 2번차, 3번차)로 혐기적으로 처리하여, ${\gamma}-aminobutyric$ acid(GABA) 및 기타 주요성분의 함량변화를 측정한 결과 차엽의 질소가스 치환처리 및 진공처리 모두 GABA와 alanine의 함량은 현저하게 증가한 반면에 glutamic acid는 현저하게 감소하였다. 또한 theanine, arginine, caffein 및 polyphenol의 함량은 거의 변화가 없었으며, vit.C의 함량은 혐기처리 시간의 경과에 따라 조금씩 감소하는 것으로 나타났다. 혈압강하작용 성분인 GABA의 생성량은 원엽의 아미노산의 함량, 특히 glutamic acid의 함량에 비례하였으며, 최적 혐기처리 시간은 약 12시간으로 나타났다. 한편, 차엽의 혐기적 처리조건에 있어서 질소가스 치환 처리와 진공처리 사이의 효과에 있어서의 차이는 거의 없었다.

• Preventive Nutrition and Food Science
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• 제15권3호
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• pp.229-232
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• 2010

Caffeine and catechins from the Yabukita, Yutakamidori, Saemidori, Okumidori, and Fushun varieties of tea leaves picked during different harvesting seasons from April to October were evaluated using HPLC. Total content of catechins increased greatly with the later harvesting time of tea leaves (i.e., picking the leaves in September versus in April) and decreased slightly after September. Yabukita tea leaves picked in August contained 43.1 mg% catechins including EGC, EC, ECG, and EGCG, with the ECGC levels constituting greater than 50% of those four compounds. Yutakamidori and Okumidori varieties picked in September contained the highest catechin values, at 43.6 mg% and 31.0 mg%, respectively. Fushun and Saemidori varieties contained lower catechin concentrations of 14.5 mg% (July) and 11.7 mg% (August) compared to other varieties. The EGCG levels gradually decreased in the late harvesting season, while levels of the other catechins, EC, EGC, and ECG, gradually increased. All varieties of green tea showed a gradual decrease in caffeine content toward the end of our harvesting efforts in October, with levels of 58～68 mg% in April and 28～57 mg% in October. Yabukita, Saemidori, and Okumidori varieties reached their highest caffeine levels in late spring/early summer, with Yabukita and Okumidori varieties reaching a high of 73.4% and 63.5% caffeine, respectively, in May, and Saemidori at 64.0% in June. In particular, Fushun still contained high caffeine of 66.8 mg% (September) during the late harvesting season.